Cramping device



Aug- 26 1924.

W. S. GR'AFFAM GRAMPING DEVICE Filed Aug. 7, 1923 Patented Au 26, 1924. 1,506,48l

UNITED STATES PATENT OFFICE.

WALTER S. GRAFFAM. OF SHREWSBURY, MASSACHUSETTS.

CRAMPING DEVICE.

Application filed August 7, 7.923. Serial No. 656,256.

To all whom it may concern: into one of the cylindrical openings of the Be it known that I, WALTER S. GRAFFAM, frame 1, or headed over on the bottom end a citizen of the United States, residing at as an ordinary rivet. Shrewsbury, in the county of l/Vorcester and The screw 4., has a formed head 7, which State of Massachusetts, have invented new may be knurled or flattened to any shape deand useful Improvements in Cramping Desirable. I vices, of which the following is a specifica- The formed washer 8, has a cupped shaped don, hole through the center into which the re- My invention relates to improvements in duced end 9, of the screw 4 is inserted and 10 mechanical cramping or clamping devices, lightly headed over to prevent the washer for holding articles together by means of 8 from dropping off, while permitting it to screw pressure. rotate freely.

The principal objects of the invention are, I am aware that prior to my invent-ion, C first, to provide a cramp, the frame of which cramps have been made in many ways, so 15 can be made of a single piece pressed sheet I do not claim the fundamental principle of metal, so formed as to give it maximum this kind of a holding or cramping device.

strength combined with lightness; and, sec- Although I have illustrated and described 0nd, to so construct it that it can be manuonly a single embodiment of the invention, factured cheaply. I am aware of the fact that many modifica- I attain these objects by the mechanism tions can be made therein by any person illustrated in the accompanylng drawing, skilled 1n the art Without departing from in which the scope of the invention as expressed in Fig. 1 is a plan view of the assembled the claims. cramp; Therefore, I do not wish to be limited to 25 Fig. 2 is a bottom View; all the details of construction herein shown Fig. 3 is a section on the line AA; and described, but what I do claim is: Fig. 4 is a section through the center on In a cramping device shaped like the letthe line BB. ter C, the combination of a frame made Similar numerals refer to similar parts from a single piece of sheet metal, with a 30 throughout the several views. central opening having flanges drawn up The frame 1 is made of a single piece of around the sides of said central opening; the sheet metal, cut or stamped out to the de metal folded back upon itself so as to leave sired shape, folded back upon itself, and two cylindrical shaped openings the axes of having flanges 2 drawn outwardly along the which lie in the same straight line; the two three sides of a central opening. When the halves of the folded metal held together as metal is folded back upon itself it is so one piece by rivets or other commonly used formed as to leave two cylindrical openings methods; an anvil inserted into one of the into one of which the anvil 3 is inserted, the cylindrical shaped openings, a screw threadsecond one being threaded to receive the ed into the other of said cylindrical open-- 40 screw 4. ings; a cupped Washer attached loosely to S5 The frame 1 is fastened firmly together the end of said screw; all substantially as by means of rivets 5, or by other commonly described and set forth. used methods such as welding, brazing or In testimony whereof I have hereunto afsoldering. fixed my signature. 45 The anvil 3 has a shank 6 which is forced WALTER S. GRAFFAM. 

